Response Header Logging

Not sure what I am doing wrong. Or if I am just missing something or if it is not possible. But I want to log some response headers in the access logs. I have seen posts that make it appear possible and also others that make me unsure if it is possible. I am running traefik in a k8s cluster and I can see the response header in dev tools... but not in the logs.. my access logs are setup like this...

  format: json
    defaultMode: keep
      defaultMode: keep

And I can see all the request headers, just not the response headers... I am writing X-Member-ID in the response header, and I do not have any logs with the response_ prefix and also none with Member.

I have done this for years with HAProxy and just assumed that it would be possible with traefik.

The docs are very unclear if response headers are included, since it does not make any references to them one way or another... and basically everything is just called headers (not prefixed by request or response)